using System;
namespace SilverlightPlayground.RFB
{
    public static class RfbEncryption
    {
        public const int MaxPasswdLen = 8;

        /// <summary>
        /// Encrypts the bytes.
        /// </summary>
        /// <param name="bytes">The bytes.</param>
        /// <param name="passwd">The passwd.</param>
        public static void EncryptBytes(byte[] bytes, string passwd)
        {
            byte[] rawKey = new byte[MaxPasswdLen];
            for (int i = 0; i < MaxPasswdLen; i++)
            {
                if (i < passwd.Length)
                    rawKey[i] = (byte)passwd[i];
                else
                    rawKey[i] = 0;
            }

            D3DesKey key = new D3DesKey(rawKey, EncryptMode.EN0);

            D3Des.Des(bytes, bytes, RfbSize.AuthenticationChallenge, key);
        }

        public class D3Des
        {
            private static UInt32[] sp1 = new UInt32[64]
            {
              0x01010400, 0x00000000, 0x00010000, 0x01010404,
              0x01010004, 0x00010404, 0x00000004, 0x00010000,
              0x00000400, 0x01010400, 0x01010404, 0x00000400,
              0x01000404, 0x01010004, 0x01000000, 0x00000004,
              0x00000404, 0x01000400, 0x01000400, 0x00010400,
              0x00010400, 0x01010000, 0x01010000, 0x01000404,
              0x00010004, 0x01000004, 0x01000004, 0x00010004,
              0x00000000, 0x00000404, 0x00010404, 0x01000000,
              0x00010000, 0x01010404, 0x00000004, 0x01010000,
              0x01010400, 0x01000000, 0x01000000, 0x00000400,
              0x01010004, 0x00010000, 0x00010400, 0x01000004,
              0x00000400, 0x00000004, 0x01000404, 0x00010404,
              0x01010404, 0x00010004, 0x01010000, 0x01000404,
              0x01000004, 0x00000404, 0x00010404, 0x01010400,
              0x00000404, 0x01000400, 0x01000400, 0x00000000,
              0x00010004, 0x00010400, 0x00000000, 0x01010004
            };

            private static UInt32[] sp2 = new UInt32[64]
            {
              0x80108020, 0x80008000, 0x00008000, 0x00108020,
              0x00100000, 0x00000020, 0x80100020, 0x80008020,
              0x80000020, 0x80108020, 0x80108000, 0x80000000,
              0x80008000, 0x00100000, 0x00000020, 0x80100020,
              0x00108000, 0x00100020, 0x80008020, 0x00000000,
              0x80000000, 0x00008000, 0x00108020, 0x80100000,
              0x00100020, 0x80000020, 0x00000000, 0x00108000,
              0x00008020, 0x80108000, 0x80100000, 0x00008020,
              0x00000000, 0x00108020, 0x80100020, 0x00100000,
              0x80008020, 0x80100000, 0x80108000, 0x00008000,
              0x80100000, 0x80008000, 0x00000020, 0x80108020,
              0x00108020, 0x00000020, 0x00008000, 0x80000000,
              0x00008020, 0x80108000, 0x00100000, 0x80000020,
              0x00100020, 0x80008020, 0x80000020, 0x00100020,
              0x00108000, 0x00000000, 0x80008000, 0x00008020,
              0x80000000, 0x80100020, 0x80108020, 0x00108000
            };

            private static UInt32[] sp3 = new UInt32[64]
            {
              0x00000208, 0x08020200, 0x00000000, 0x08020008,
              0x08000200, 0x00000000, 0x00020208, 0x08000200,
              0x00020008, 0x08000008, 0x08000008, 0x00020000,
              0x08020208, 0x00020008, 0x08020000, 0x00000208,
              0x08000000, 0x00000008, 0x08020200, 0x00000200,
              0x00020200, 0x08020000, 0x08020008, 0x00020208,
              0x08000208, 0x00020200, 0x00020000, 0x08000208,
              0x00000008, 0x08020208, 0x00000200, 0x08000000,
              0x08020200, 0x08000000, 0x00020008, 0x00000208,
              0x00020000, 0x08020200, 0x08000200, 0x00000000,
              0x00000200, 0x00020008, 0x08020208, 0x08000200,
              0x08000008, 0x00000200, 0x00000000, 0x08020008,
              0x08000208, 0x00020000, 0x08000000, 0x08020208,
              0x00000008, 0x00020208, 0x00020200, 0x08000008,
              0x08020000, 0x08000208, 0x00000208, 0x08020000,
              0x00020208, 0x00000008, 0x08020008, 0x00020200
            };

            private static UInt32[] sp4 = new UInt32[64]
            {
              0x00802001, 0x00002081, 0x00002081, 0x00000080,
              0x00802080, 0x00800081, 0x00800001, 0x00002001,
              0x00000000, 0x00802000, 0x00802000, 0x00802081,
              0x00000081, 0x00000000, 0x00800080, 0x00800001,
              0x00000001, 0x00002000, 0x00800000, 0x00802001,
              0x00000080, 0x00800000, 0x00002001, 0x00002080,
              0x00800081, 0x00000001, 0x00002080, 0x00800080,
              0x00002000, 0x00802080, 0x00802081, 0x00000081,
              0x00800080, 0x00800001, 0x00802000, 0x00802081,
              0x00000081, 0x00000000, 0x00000000, 0x00802000,
              0x00002080, 0x00800080, 0x00800081, 0x00000001,
              0x00802001, 0x00002081, 0x00002081, 0x00000080,
              0x00802081, 0x00000081, 0x00000001, 0x00002000,
              0x00800001, 0x00002001, 0x00802080, 0x00800081,
              0x00002001, 0x00002080, 0x00800000, 0x00802001,
              0x00000080, 0x00800000, 0x00002000, 0x00802080
            };

            private static UInt32[] sp5 = new UInt32[64]
            {
              0x00000100, 0x02080100, 0x02080000, 0x42000100,
              0x00080000, 0x00000100, 0x40000000, 0x02080000,
              0x40080100, 0x00080000, 0x02000100, 0x40080100,
              0x42000100, 0x42080000, 0x00080100, 0x40000000,
              0x02000000, 0x40080000, 0x40080000, 0x00000000,
              0x40000100, 0x42080100, 0x42080100, 0x02000100,
              0x42080000, 0x40000100, 0x00000000, 0x42000000,
              0x02080100, 0x02000000, 0x42000000, 0x00080100,
              0x00080000, 0x42000100, 0x00000100, 0x02000000,
              0x40000000, 0x02080000, 0x42000100, 0x40080100,
              0x02000100, 0x40000000, 0x42080000, 0x02080100,
              0x40080100, 0x00000100, 0x02000000, 0x42080000,
              0x42080100, 0x00080100, 0x42000000, 0x42080100,
              0x02080000, 0x00000000, 0x40080000, 0x42000000,
              0x00080100, 0x02000100, 0x40000100, 0x00080000,
              0x00000000, 0x40080000, 0x02080100, 0x40000100
            };

            private static UInt32[] sp6 = new UInt32[64]
            {
              0x20000010, 0x20400000, 0x00004000, 0x20404010,
              0x20400000, 0x00000010, 0x20404010, 0x00400000,
              0x20004000, 0x00404010, 0x00400000, 0x20000010,
              0x00400010, 0x20004000, 0x20000000, 0x00004010,
              0x00000000, 0x00400010, 0x20004010, 0x00004000,
              0x00404000, 0x20004010, 0x00000010, 0x20400010,
              0x20400010, 0x00000000, 0x00404010, 0x20404000,
              0x00004010, 0x00404000, 0x20404000, 0x20000000,
              0x20004000, 0x00000010, 0x20400010, 0x00404000,
              0x20404010, 0x00400000, 0x00004010, 0x20000010,
              0x00400000, 0x20004000, 0x20000000, 0x00004010,
              0x20000010, 0x20404010, 0x00404000, 0x20400000,
              0x00404010, 0x20404000, 0x00000000, 0x20400010,
              0x00000010, 0x00004000, 0x20400000, 0x00404010,
              0x00004000, 0x00400010, 0x20004010, 0x00000000,
              0x20404000, 0x20000000, 0x00400010, 0x20004010
            };

            private static UInt32[] sp7 = new UInt32[64]
            {
              0x00200000, 0x04200002, 0x04000802, 0x00000000,
              0x00000800, 0x04000802, 0x00200802, 0x04200800,
              0x04200802, 0x00200000, 0x00000000, 0x04000002,
              0x00000002, 0x04000000, 0x04200002, 0x00000802,
              0x04000800, 0x00200802, 0x00200002, 0x04000800,
              0x04000002, 0x04200000, 0x04200800, 0x00200002,
              0x04200000, 0x00000800, 0x00000802, 0x04200802,
              0x00200800, 0x00000002, 0x04000000, 0x00200800,
              0x04000000, 0x00200800, 0x00200000, 0x04000802,
              0x04000802, 0x04200002, 0x04200002, 0x00000002,
              0x00200002, 0x04000000, 0x04000800, 0x00200000,
              0x04200800, 0x00000802, 0x00200802, 0x04200800,
              0x00000802, 0x04000002, 0x04200802, 0x04200000,
              0x00200800, 0x00000000, 0x00000002, 0x04200802,
              0x00000000, 0x00200802, 0x04200000, 0x00000800,
              0x04000002, 0x04000800, 0x00000800, 0x00200002
            };

            private static UInt32[] sp8 = new UInt32[64]
            {
              0x10001040, 0x00001000, 0x00040000, 0x10041040,
              0x10000000, 0x10001040, 0x00000040, 0x10000000,
              0x00040040, 0x10040000, 0x10041040, 0x00041000,
              0x10041000, 0x00041040, 0x00001000, 0x00000040,
              0x10040000, 0x10000040, 0x10001000, 0x00001040,
              0x00041000, 0x00040040, 0x10040040, 0x10041000,
              0x00001040, 0x00000000, 0x00000000, 0x10040040,
              0x10000040, 0x10001000, 0x00041040, 0x00040000,
              0x00041040, 0x00040000, 0x10041000, 0x00001000,
              0x00000040, 0x10040040, 0x00001000, 0x00041040,
              0x10001000, 0x00000040, 0x10000040, 0x10040000,
              0x10040040, 0x10000000, 0x00040000, 0x10001040,
              0x00000000, 0x10041040, 0x00040040, 0x10000040,
              0x10040000, 0x10001000, 0x10001040, 0x00000000,
              0x10041040, 0x00041000, 0x00041000, 0x00001040,
              0x00001040, 0x00040040, 0x10000000, 0x10041000
            };

            /// <summary>
            /// Scrunches the specified out of.
            /// </summary>
            /// <param name="outOf">The out of.</param>
            /// <param name="offset">The offset.</param>
            /// <param name="into">The into.</param>
            private static void Scrunch(byte[] outOf, UInt32 offset, UInt32[] into)
            {
                into[0] = (UInt32)outOf[offset] << 24 | (UInt32)outOf[offset + 1] << 16 | (UInt32)outOf[offset + 2] << 8 | (UInt32)outOf[offset + 3];
                into[1] = (UInt32)outOf[offset + 4] << 24 | (UInt32)outOf[offset + 5] << 16 | (UInt32)outOf[offset + 6] << 8 | (UInt32)outOf[offset + 7];
            }

            /// <summary>
            /// Uns the scrun.
            /// </summary>
            /// <param name="outOf">The out of.</param>
            /// <param name="into">The into.</param>
            /// <param name="offset">The offset.</param>
            private static void UnScrunch(UInt32[] outOf, byte[] into, UInt32 offset)
            {
                into[offset] = (byte)((outOf[0] >> 24) & 0x000000FF);
                into[offset + 1] = (byte)((outOf[0] >> 16) & 0x000000FF);
                into[offset + 2] = (byte)((outOf[0] >> 8) & 0x000000FF);
                into[offset + 3] = (byte)(outOf[0] & 0x000000FF);
                into[offset + 4] = (byte)((outOf[1] >> 24) & 0x000000FF);
                into[offset + 5] = (byte)((outOf[1] >> 16) & 0x000000FF);
                into[offset + 6] = (byte)((outOf[1] >> 8) & 0x000000FF);
                into[offset + 7] = (byte)(outOf[1] & 0x000000FF);
            }

            /// <summary>
            /// DESs the func.
            /// </summary>
            /// <param name="block">The block.</param>
            /// <param name="key">The key.</param>
            private static void DesFunc(UInt32[] block, D3DesKey key)
            {
                UInt32 work;

                UInt32 leftt = block[0];
                UInt32 right = block[1];
                work = ((leftt >> 4) ^ right) & 0x0F0F0F0F;
                right ^= work;
                leftt ^= (work << 4);
                work = ((leftt >> 16) ^ right) & 0x0000FFFF;
                right ^= work;
                leftt ^= (work << 16);
                work = ((right >> 2) ^ leftt) & 0x33333333;
                leftt ^= work;
                right ^= (work << 2);
                work = ((right >> 8) ^ leftt) & 0x00FF00FF;
                leftt ^= work;
                right ^= (work << 8);
                right = ((right << 1) | ((right >> 31) & 1)) & 0xFFFFFFFF;
                work = (leftt ^ right) & 0xAAAAAAAA;
                leftt ^= work;
                right ^= work;
                leftt = ((leftt << 1) | ((leftt >> 31) & 1)) & 0xFFFFFFFF;

                int keyIndex = 0;
                for (int round = 0; round < 8; round++)
                {
                    UInt32 fval;

                    work = (right << 28) | (right >> 4);
                    work ^= key[keyIndex++];
                    fval = sp7[work & 0x3F];
                    fval |= sp5[(work >> 8) & 0x3F];
                    fval |= sp3[(work >> 16) & 0x3F];
                    fval |= sp1[(work >> 24) & 0x3F];
                    work = right ^ key[keyIndex++];
                    fval |= sp8[work & 0x3F];
                    fval |= sp6[(work >> 8) & 0x3F];
                    fval |= sp4[(work >> 16) & 0x3F];
                    fval |= sp2[(work >> 24) & 0x3F];
                    leftt ^= fval;
                    work = (leftt << 28) | (leftt >> 4);
                    work ^= key[keyIndex++];
                    fval = sp7[work & 0x3F];
                    fval |= sp5[(work >> 8) & 0x3F];
                    fval |= sp3[(work >> 16) & 0x3F];
                    fval |= sp1[(work >> 24) & 0x3F];
                    work = leftt ^ key[keyIndex++];
                    fval |= sp8[work & 0x3F];
                    fval |= sp6[(work >> 8) & 0x3F];
                    fval |= sp4[(work >> 16) & 0x3F];
                    fval |= sp2[(work >> 24) & 0x3F];
                    right ^= fval;
                }

                right = (right << 31) | (right >> 1);
                work = (leftt ^ right) & 0xAAAAAAAA;
                leftt ^= work;
                right ^= work;
                leftt = (leftt << 31) | (leftt >> 1);
                work = ((leftt >> 8) ^ right) & 0x00FF00FF;
                right ^= work;
                leftt ^= (work << 8);
                work = ((leftt >> 2) ^ right) & 0x33333333;
                right ^= work;
                leftt ^= (work << 2);
                work = ((right >> 16) ^ leftt) & 0x0000FFFF;
                leftt ^= work;
                right ^= (work << 16);
                work = ((right >> 4) ^ leftt) & 0x0F0F0F0F;
                leftt ^= work;
                right ^= (work << 4);
                block[0] = right;
                block[1] = leftt;
            }

            /// <summary>
            /// DESs the specified from.
            /// </summary>
            /// <param name="from">From.</param>
            /// <param name="to">To.</param>
            /// <param name="length">The length.</param>
            /// <param name="key">The key.</param>
            public static void Des(byte[] from, byte[] to, int length, D3DesKey key)
            {
                UInt32[] work = new UInt32[2];
                for (int i = 0; i < length; i += 8)
                {
                    Scrunch(from, (UInt32)i, work);
                    DesFunc(work, key);
                    UnScrunch(work, to, (UInt32)i);
                }
            }
        }

        public enum EncryptMode : short
        {
            EN0 = 0,
            DE1 = 1
        }

        public class D3DesKey
        {
            private static UInt16[] bytebit = new UInt16[8]
            {
              0x0001, 0x0002, 0x0004, 0x0008, 0x0010, 0x0020, 0x0040, 0x0080
            };

            private static UInt32[] bigbyte = new UInt32[24]
            {
              0x00800000, 0x00400000, 0x00200000, 0x00100000,
              0x00080000, 0x00040000, 0x00020000, 0x00010000,
              0x00008000, 0x00004000, 0x00002000, 0x00001000,
              0x00000800, 0x00000400, 0x00000200, 0x00000100,
              0x00000080, 0x00000040, 0x00000020, 0x00000010,
              0x00000008, 0x00000004, 0x00000002, 0x00000001
            };

            private static byte[] pc1 = new byte[56]
            {
              56, 48, 40, 32, 24, 16, 8, 0, 57, 49, 41, 33, 25, 17,
              9, 1, 58, 50, 42, 34, 26, 18, 10, 2, 59, 51, 43, 35,
              62, 54, 46, 38, 30, 22, 14, 6, 61, 53, 45, 37, 29, 21,
              13, 5, 60, 52, 44, 36, 28, 20, 12, 4, 27, 19, 11, 3
            };

            private static byte[] pc2 = new byte[48]
            {
              13, 16, 10, 23, 0, 4, 2, 27, 14, 5, 20, 9,
              22, 18, 11, 3, 25, 7, 15, 6, 26, 19, 12, 1,
              40, 51, 30, 36, 46, 54, 29, 39, 50, 44, 32, 47,
              43, 48, 38, 55, 33, 52, 45, 41, 49, 35, 28, 31
            };

            private static byte[] totrot = new byte[16]
            {
              1, 2, 4, 6, 8, 10, 12, 14, 15, 17, 19, 21, 23, 25, 27, 28
            };

            private UInt32[] knL = new UInt32[32];

            public UInt32 this[int index]
            {
                get
                {
                    return knL[index];
                }
            }

            /// <summary>
            /// Cookeys the specified raw.
            /// </summary>
            /// <param name="raw">The raw.</param>
            private void Cookey(UInt32[] raw)
            {
                int j;
                for (int i = 0; i < 32; i += 2)
                {
                    j = i + 1;
                    knL[i] = (raw[i] & 0x00FC0000) << 6;
                    knL[i] |= (raw[i] & 0x00000FC0) << 10;
                    knL[i] |= (raw[j] & 0x00FC0000) >> 10;
                    knL[i] |= (raw[j] & 0x00000FC0) >> 6;
                    knL[j] = (raw[i] & 0x0003F000) << 12;
                    knL[j] |= (raw[i] & 0x0000003F) << 16;
                    knL[j] |= (raw[j] & 0x0003F000) >> 4;
                    knL[j] |= (raw[j] & 0x0000003F);
                }
            }

            /// <summary>
            /// Initializes a new instance of the <see cref="D3DesKey"/> class.
            /// </summary>
            /// <param name="key">The key.</param>
            /// <param name="mode">The mode.</param>
            public D3DesKey(byte[] key, EncryptMode mode)
            {
                int l;
                int m;

                byte[] pc1m = new byte[56];
                byte[] pcr = new byte[56];
                UInt32[] kn = new UInt32[32];

                for (int j = 0; j < 56; j++)
                {
                    l = pc1[j];
                    m = l & 7;
                    pc1m[j] = (byte)((key[l >> 3] & bytebit[m]) != 0 ? 1 : 0);
                }
                for (int i = 0; i < 16; i++)
                {
                    int n;

                    if (mode == EncryptMode.DE1)
                        m = (15 - i) << 1;
                    else if (mode == EncryptMode.EN0)
                        m = i << 1;
                    else
                        throw new ArgumentException("mode", "Not a valid encryption mode");
                    n = m + 1;
                    kn[m] = 0;
                    kn[n] = 0;
                    for (int j = 0; j < 28; j++)
                    {
                        l = j + totrot[i];
                        if (l < 28)
                            pcr[j] = pc1m[l];
                        else
                            pcr[j] = pc1m[l - 28];
                    }
                    for (int j = 28; j < 56; j++)
                    {
                        l = j + totrot[i];
                        if (l < 56)
                            pcr[j] = pc1m[l];
                        else
                            pcr[j] = pc1m[l - 28];
                    }
                    for (int j = 0; j < 24; j++)
                    {
                        if (pcr[pc2[j]] != 0)
                            kn[m] |= bigbyte[j];
                        if (pcr[pc2[j + 24]] != 0)
                            kn[n] |= bigbyte[j];
                    }
                }

                Cookey(kn);
            }
        }

    }
}
